Some do, but expect fewer departures.

Yes, but not all, and not as often.

Boat tours in tourist-heavy areas (like warm-weather spots or protected harbors) often run year-round, just on a reduced schedule. November through March usually means fewer departures per day, maybe one or two instead of four or five. In colder climates or places with rough winter seas, many operators shut down completely or only run by private charter.

The real answer depends on where you are. In the Florida Keys or the Caribbean, tours run most days. In New England or the Pacific Northwest, you’ll be lucky to find one. Always call ahead or check the website—don’t trust the general “year-round” label. Also, off-season tours often have stricter weather cancelation policies.

My take: if you’re planning a trip in the off-season, assume tours are limited and be ready to pivot. Book in advance if you find one running.